/*******************************************************************************
 * Copyright (c) 2014 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 *
 * The Eclipse Public License is available at
 *    http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Ian Craggs - initial API and implementation and/or initial documentation
 *******************************************************************************/

#include "StackTrace.h"
#include "MQTTSNPacket.h"

int MQTTSNDeserialize_unsubscribe(unsigned short* packetid, MQTTSN_topicid* topicFilter,
        unsigned char* buf, int buflen)
{
    MQTTSNFlags flags;
    unsigned char* curdata = buf;
    unsigned char* enddata = NULL;
    int rc = 0;
    int mylen = 0;

    FUNC_ENTRY;
    curdata += MQTTSNPacket_decode(curdata, buflen, &mylen); /* read length */
    enddata = buf + mylen;
    if (enddata - curdata > buflen)
    {
        goto exit;
    }

    if (readMQTTSNChar(&curdata) != MQTTSN_UNSUBSCRIBE)
    {
        goto exit;
    }

    flags.all = readMQTTSNChar(&curdata);
    *packetid = readMQTTSNInt(&curdata);

    topicFilter->type = (MQTTSN_topicTypes)flags.bits.topicIdType;
    if (topicFilter->type == MQTTSN_TOPIC_TYPE_NORMAL)
    {
        topicFilter->data.long_.len = enddata - curdata;
        topicFilter->data.long_.name = (char*)curdata;
    }
    else if (topicFilter->type == MQTTSN_TOPIC_TYPE_PREDEFINED)
        topicFilter->data.id = readMQTTSNInt(&curdata);
    else if (topicFilter->type == MQTTSN_TOPIC_TYPE_SHORT)
    {
        topicFilter->data.short_name[0] = readMQTTSNChar(&curdata);
        topicFilter->data.short_name[1] = readMQTTSNChar(&curdata);
    }

    rc = 1;
exit:
    FUNC_EXIT_RC(rc);
    return rc;
}


int MQTTSNSerialize_unsuback(unsigned char* buf, int buflen, unsigned short packetid)
{
    unsigned char *ptr = buf;
    int len = 0;
    int rc = 0;

    FUNC_ENTRY;
    if ((len = MQTTSNPacket_len(3)) > buflen)
    {
        rc = MQTTSNPACKET_BUFFER_TOO_SHORT;
        goto exit;
    }
    ptr += MQTTSNPacket_encode(ptr, len); /* write length */
    writeMQTTSNChar(&ptr, MQTTSN_UNSUBACK);      /* write message type */

    writeMQTTSNInt(&ptr, packetid);

    rc = ptr - buf;
exit:
    FUNC_EXIT_RC(rc);
    return rc;
}


